1. Field of the Invention
The present invention relates to an information processing apparatus, an information recording medium, an information processing method, and a program. More particularly, the present invention relates to an information processing apparatus, an information recording medium, an information processing method, and a program whereby the usage of content recorded onto an information recording medium is controlled.
2. Description of the Related Art
Various discs such as DVDs (Digital Versatile Discs) and Blu-ray Discs™ are used as recording media for a variety of content, such as movies and music. Much of the content recorded onto such discs is protected by copyright, distribution rights, or other rights held by the content creator or seller. For this reason, usage controls are enacted in order to prevent unauthorized usage.
For example, a control program or system may be used in order to prevent unauthorized copying of content recorded on-disc, or to limit the number of such copies. In addition, a usage control technique may also be used wherein the content is stored on-disc in an encrypted manner, and a key is set such that only users or equipment having proper content usage rights are able to acquire the key. A content usage control configuration using content encryption is disclosed in Japanese Unexamined Patent Application Publication No. 2003-116100, for example.
One standard for content copy protection technology is AACS (Advanced Access Content System). AACS stipulates that a media ID or similar ID information is used when accessing content that has been recorded on-disc. For example, in a playback sequence conducted according to the AACS standard, a playback apparatus into which a disc has been loaded first reads a media ID from the disc, and then executes processing to validate the read ID and generate a key using the ID information, for example. The encrypted content stored on-disc is then decrypted using the generated key, and the content is subsequently played back.
A variety of content usage control schemes like the above have been proposed. However, many of these schemes are either-or controls, and only determine whether or not usage is authorized for the controlled content recorded on-disc. In other words, many schemes distinguish between just two types of users, wherein authorized users are allowed to access all controlled content stored on-disc, while unauthorized users are not allowed to access any controlled content.
In contrast, there are a variety of scenarios whereby a disc storing content might be provided to or used by a user, such as:
(a) usage of content on a disc fully purchased at a retail store;
(b) usage of content on a disc rented via a rental service; and
(c) usage of content on a disc distributed to users free of charge as a promotional item.
Content can thus be provided to users by a variety of different routes. If the content stored on such different discs is identical, then the content accessed by an authorized user is identical in all cases, regardless of whether the user purchased the disc, rented the disc, or received the disc free of charge as a promotional item.
In contrast, a content owner who provides content might wish to conduct different usage controls on a per-user basis, such as:
(a) authorizing the main title content of a movie as well as premium content for users who purchased the disc;
(b) authorizing only the main title content of a movie for users renting the disc; and
(c) authorizing only trailers of movie content for users whose received a promotional disc.
In order to control usage for different scenarios as above, a method may be used wherein three types of discs with respectively different stored content are manufactured, with a different disc type being used for each provision route. However, the above involves creating three different master discs to be used as masters for manufacturing the three different types of discs, resulting in significant increases in cost.
An alternative method may also be used, wherein the content stored on-disc is identical for all discs, and respective sets of content are encrypted using different encryption keys, with a key being selected according to the user and then provided from a server. In other words, the encryption key for the main title content of a movie, the encryption key for the premium content, and the encryption key for the trailers of movie content are made to respectively differ from each other, and a key that has been selected according to one of the above disc types (a) to (c) are provided from a server.
When executing the above processing, a user apparatus into which a disc has been loaded first transmits the media ID recorded onto that disc to a server. The server subsequently selects a key according to media ID information managed by the server, and then provides the selected key to the user. However, there is a problem with this method in that playback devices not provided with functions for communicating over a network might not be able to acquire a key from the server, and thus might not be able to access the content.